Commodore VIC-20 Technical Manual
The Commodore VIC-20 Technical Manual, cover title The Friendly Computer Technical Manual, Model VIC-20, is Commodore's 25-page technical manual, part number P/N 990440. Like the C64 manual (990439) and the PET 4000 manual (990438), it is a package of engineering drawings with no narrative text. It covers both VIC-20 main boards: the early assembly 324003 (2-pin power connector) and the VIC-20CR assembly 250403 (7-pin DIN).
Commodore's notice on the inside cover reads: "These documents are for repair service information only. Part numbers are for reference only."
The scan has a text layer, but the OCR of the handwritten drawings is poor; read values from the images.
Contents
[edit | edit source]| Pages | Content |
|---|---|
| 1-2 | Cover and service notice |
| 3 | Drawing tree: shipping assembly 324030-01 (with AC adaptor, user manual, RF cable and RF switch box), main assembly 324020-01, base assembly 324027-01, cover assembly 324025-01, PCB assembly 324003-01, LED assembly 1001039-01, jumper cable assembly 324033-01 and RF modulator assembly 321453 |
| 4-6 | Three-sheet main logic schematic for the early board, with transistor substitution notes (2SC1959 for Q6 and Q7, 2SC1815 for Q3, Q4 and Q5) |
| 7-11 | Component parts list for PCB assembly 324003, titled VIC-1001 PCB ASSY: dash numbers -02 (PCB assy USA), -05 and -09 (NTSC, USA and Canada), revisions A to M with their ECO numbers. The NTSC 6560 VIC (item 16) and the 14.31818 MHz crystal (item 86) have a quantity in all three versions; the PAL 6561 (item 17, p. 8) and the 8.867236 MHz crystal (item 87, p. 10) are listed with no quantity in any of them |
| 12 | Board assembly drawing |
| 13 | Drawing tree for the later machine |
| 14-16 | VIC-20CR schematic 251027-01, three sheets; one is annotated "SCHEMATIC DIAGRAM (NTSC) WITHOUT PAL" |
| 17-21 | Component parts list for PCB assembly 250403 (VIC-20CR), dash number -02 (PCB assy USA), revisions A to E with ECOs 820034 to 830010 |
| 22-23 | PCB artwork |
| 24-25 | Assembly drawings (p. 24 is for the 250403 board) |
What this manual settles
[edit | edit source]- It has component parts lists and schematics for both board assemblies. A capacitor or chip designator only means something with the assembly number attached.
- VR1 on the 324003 board is an LM323 (901528-01), fed through a bridge rectifier and the 4700 µF 16 V reservoir C39; the 250403 board has no voltage regulator. Commodore's Version E main logic schematic, hosted separately as File:Commodore VIC-20 Schematic (Version E).pdf, numbers the same 4700 µF 16 V reservoir C1, so check which drawing a designator comes from.
- The crystal part numbers for NTSC (14.31818 MHz) and PAL (8.867236 MHz) machines, and the fuse ratings: 3 A slow-blow on the 324003, 1 A slow-blow on the 250403.
What this manual does not contain
[edit | edit source]- No troubleshooting guide, no circuit theory and no symptom tables.
- No external power-supply internals.
- No usable text layer for the drawings, so the parts lists cannot be searched.
Pages that cite this document
[edit | edit source]- Commodore VIC-20: board assemblies, regulator, crystals, VIC supply
- Commodore VIC-20 General Maintenance: power input, fuses, chip positions
- Commodore VIC-20 Troubleshooting Guide
- Commodore VIC-20 Capacitor Replacement Guide: both capacitor lists
- Commodore PET 2001 Capacitor Replacement Guide: 6502 pin assignments
Download: Commodore VIC-20 Technical Manual.pdf